On the 5R55E or 44E, the automatics the Rangers use, the TSS sensor is inside the transmission
The 5R55W and S do have external TSS
Seen here:
https://ww2-secure.justanswer.com/uploads/KE/kennyz1963/2013-09-26_124735_tss.gif
In 2001 Rangers got an ISS sensor located on the outside above shift rod
So yes transmission needs to come out and be disassembled to replace the TSS sensor IF..............thats the problem
Could just be a bad wire, since its a "circuit code"
You can unplug the 16 pin connector on drivers side of transmission and use an OHM meter to test TSS sensor
Drawing here
View attachment 52390
It is possible for one of the TSS wires to break inside the pan on the harness, so if external wires TSS + and - don't show a connection, you could drop the pan and check.....................but longshot